Key for cable-testing



PATENTE@ PEB. 16; w04.

W. B. HALE KEY EGR CABLE TESTING.

APPLICATION FILED PR. 29.19GL

No, 752,l58.

m Mann.

UNITED STATES Patented February 16, 1904.

PATENT x OEETQE, .1

BUELL HALE, or CHICAGO,v Timers, Assis-Nostro WESTERN ELECJIEIC COMPANY, CE mentors.

srncmca'noN fcrming'pm of letters Patent No. vsaiss, it`

KEY Fon @ABLE-TESTING.

Applications@ Apri129,'19o1..serinn. 57,952. 'm0 maar f To aZZ whom it may Beit known'that I, .BUELL HALE, a citizen'of the United States, residing at Chicago, in the county oi Cook and State oIllinois, have invented a. certain new and useful Improvement in Keysjor Cableflestingl of which the following isa full, clear, concise,

.and exact description.- v n Y changes and be pointed gram illustrating the several-circuitlchanges insulating pillar. .posts d' d2v pillars .in line with the switch-levend, posts carrying platinumcontact-anvils c c? o3,

'35 under side of the switch-lever endgis adapted when the leveris depressed toi The con-v tact a? is mounted on' theuppersurface of the.

. spending contact-points of My invention relates v.to atesting-key; and

all

Figure 1 is a of my invention, and Fig. sectional view thereof in association with a diavvhichmay' be'eected by its use.

In the particular embodiment of my invenl tion which I have chosen to illustrate, the-main lever or switch-arm a is pivoted at its end to al metallic post mounted upon the top of au Three metallic Contact# Z3 are mounted upon insulating sai which are adapted to be engaged by correythe switch-lever. The contact-point a', which ismounted on the nearits outer strike thclanvil c of the post d'.

e leveris-l in its lever and )is adapted when t elevated positionto engage with the discharge contact-point c3 upon the end-0f the screw d,

. which is mounted on the post "The spring bftends to maintain the lever a normally 1n elevated position, as shown in Fig.

Vhead of the screw astening'the V.button or handle g tothe spring, ismounted cables maybe effected with aci- 2 is a longitudinalthird @neepoint is @fried feyatteint of a screwe, mounted' upon ametallic spring f, which'is screwed the' topbf the switchleverl a. The end of the spring fis provided with an insulating-button `guby which it may be depressed. A stud g', which Vmaybe lthe linslilating bn the under surface of" thespringxin suchfa t way that when the button depressed the grisstud g' yvvill. strike the surface of the switch#d lever ci, whereby both the contactpoint a2 and the switch-lever' a may g. The spring f, with-the 'ccntactticarri be depressed at the'. same time by simply pressinglupon the butteeiV thereby, thus constitutes Whatlterma supf plemental or auxiliary? `keymeunted upon A themaiu switch-arm. Botlrthecontact-anvils c and c2 are preferahlyspringmounted, -as

' l f .55, mountedgopposite the shown most clearly i.31` Fig.-2.v f A rocking leverf-h end of the switch-leven(uV said 'rocking lever carrying an insulated detent 'or catch h", which is adapted to engage-the end -o the .switchlever and hold it downwhenonce saidleveris depressed. This llevend/isyieldingly held over against theend -of the V svs'ritchleverl arm c by a spring k', as shown. Besides serving -tohold down the svviteli-armfa'l the Avrocking lever his adapted', when it ismoved over to;

the 'lever,-to` bring av screw contact-pointeared therebyintolen-f the right in releasinggagenient with' afspring*` meunted anvil Z The sainement `se sie svemifcomattoineis such that when? theflever isgrst depressed'- by pressing,enA the knobthejlcontact ai c2 will'rst he closed and'then 'afmomentgafterwardv4 the contact affc' "be'closedt- Then on releasing the*- jressure the-"switch-arm a will be held down? but thespring?ei` supplemental key 'f Wil'l moved upward by its Yown resiliency a suilicientdistanelso that the "contact-pointe?" be separated from the auvild- ATo'release the svfvitcli-arm c, the

A l rocking lever is {meved over"te theright;

r1-tente but the adjustment is such that the contact Will be closed before the switch-arm is released to make the contact (15; c3.

The operation of the hey may be readily understood by considering Fie'. 2. The contact-anvil cis connected With e grounded source oi' current D, suitable for testing, and the post upon which the switch-arm o is mounted, is connected through the galvanometer G with the Wire of the cable to be tested. The sheath ci' the cabie, as neue-hie Y The contact Z contrclsa shunt;

grounded. around the galvanometer, including el predetermined resistance, to be used when the cable is discharged. The contact ed is connected to ground, andthe Contact c2 is connected directly with the wire ot thecable- .to ,be tested, so that when the contact 0,2 c is close-d the galvenometer will be' shoi't--circuited- In operating the key the knob y is first pushed down, so 'depressing the switch-erin a until both contacts a" c and c2 o2 are made. Then on releasing the pressure the spring f moves up and separates 'the 'contact-points' a2 c2, so that the current-from the generator Dnds paththrough the galaf'enonieter to the l .Wire of the cable being; tested and thence to f by noting the deil'ection of the gaivanorneter.

jearth. By noting the deliection of the galvanometer the insulation resistance oi the cable may be determined.

When the operator is ready to take the capacity reading7 of the cable, he pulls the discharge-release level' L, which lirst establishes at Contact Z the shunt-circuit about the galvanorneter, including resistance R, and

'then releases the arin af, which moves up,

ybreakingthe battery connection c and closing the discharge-contact e. vThe cable acting as a condenser is thus discharged throughy the galvanorneter and the v shunt thereof, and

the capacity may be determined. The resistance' R ofcourse is connected in shunt of the igalvanoineter, softhat ythe deiiection Will be4 smaller than it :would otherwise be., thus permitting the saine gelvanouieter to be used for measuring both capacity and insulation resistance. f

It is apparent that theideas herein set forth may be embodied in structures diiiiering to some extent from that shown in the drawings, and Ido not desire to be understood as limiting myself to the particular device illustrated;

but, v f

Having thus described my invention, I claim as new and desire to secure l'yvLetters Fatentd vl. IIn afmeting-hey, the con'i'oination with e main switch-lever, two switch-contacts operated 'in sequence in the movement of seid switch-lever in one direction, a. deteut adac-1- 'ed to hold said switch-lever in its operative ing; said arm.

position, switch-contact operated in the movement of the detent, and a contact operated in the return of the switch-lever to its normal position. y y

f 9.-. in a testing apparatus, the combination with a source of current, a galvanonieter and shunt of the galvanometf-:i'I including a resistences oi' a main switch-lever, two switchcontacts operated in sequence through the agency ofv seid iever-When moved in one direci-Jion. one of' said contacts' controlling the connecti'on'o'f the source of current with galvancrneterendithe device to he tested., and the other of said contacts controlling; a short g circuit of 'the galvanometer, a detent adapted to. hold. the switch-lever inl its operative. position, a switch-contact `operated in the movenient of the.detent,-said switch-contact controllingv the said shunt of the gaivanouieter,

and a contac'tactuated inreturning the switch- Y lever to its normalposition, adapted todischarge the device beingtested, throughthe gaivanorneter. I f y 3. In a sWitch-keyJthe combination with closed thereby, 'of la' Qsupp'lernentall springmounted key f 'carried by saiuarm., an' independent Contact c2 controlled by'saiol supplemental Vlkey., the inain switch-arm being adapt'- ed tobe operated by operating thesujoplemental lrey, a detent o1' catch adapted to'hold the switch-arm in one' of its positionsof adjustlnent, yand a switch-,contact'controlled by said catch and operated in releasing the switcharmo, `subste ntiaily set forth:

, Li. in a sxvi.tch-hey,y the lconicin'ation with a switcharn'i a and al contact Aadapted 'to be closed thereby, of supplement-ei spring-heyy car ied by said arm, and an indepe'ndentcontact-o2 adapted 'to' be `closed bysaid' suppiementalv key, a knob g for said supplementai key., whereby bothl the suppieinental key and the Vmain switch-arm may be' depressed; sein supplemental .key when released beingadapted to lreelk itscontacte?independentlyci the switch ini, a detent-lexf'er Zi having' acatcii adapted to hold the arm c in its depressed positioinI and a, switch-contactclosed in releas- 5. in a testing ythecombination with a source'of current,"a galvanometer and a resistance, of a keycomprising a pivoted switch-arm and ycontacts closed in the alternate igiositions of vsaid aree., 'one of said contacts controliing va connection of'the source .the switch-arniend acontact adapted `to be EIO meme Y @e arm, whereby the switch-arm and the supplel by said detenbever in reeasug the swteh- I0 menta key may be depressed together, a c0nerm..

tact eont'oed by the supplemental key for in Witness-whereof hereunto Subscribe my closing a short circuit of said gavanometer, name this 26th day of March, A. D. 1901. the supplemental key bemg adapted to open ,LLAM BUELL HALE.

said short Circuit when reeased,` a detent-le- .ver for holding the switch-arm depressed, and Witnesses:

a contact eontrolng ashunt of the galvanom- ELLA EDLER, eter including the aforesaid resietance, closed E. H. SMYTHE. 

